1. Field of the Invention
The invention relates to a keyboard, and more particularly, to a keyboard in which metal plates of varying thickness may be installed.
2. Description of the Prior Art
A typical keyboard comprises a cover chassis, a base chassis, a plurality of keys installed on the cover chassis in a vertically moveable manner, and a flexible circuit board installed between the cover chassis and the base chassis for detecting operations of the keys. Some keyboards further comprise metal plates to strengthen the structure of the keyboards.
A keyboard without a metal plate is often comparatively thinner. It does not contain a space for installation of a metal plate and therefore, when a client requests a keyboard with such a metal plate, the manufacturer must build an entirely new thicker keyboard that can accommodate the metal plate. On the other hand, a keyboard with a metal plate is thick. If the metal plate is requested to be removed, the manufacturer must produce another base chassis to fill the void previously occupied by the metal plate. In addition, if a client requires a metal plate of a different thickness than that normally provided, yet another base chassis design is needed. For keyboards of the same type, electronic components in the keyboards have to be maintained at a predetermined level regardless of whether metal plates are installed or what the thickness of the keyboard is, thus the manufacturer has to produce various base chassis to comply with demands of various clients which not only increases the cost of molds, but also increases the types of components and the cost of managing various components.